MARKING METHOD AND DEVICE FOR TWO-DIMENSIONAL CODE

摘要

PROBLEM TO BE SOLVED: To provide a laser marking device and a method surely reading a reading reference part. SOLUTION: Laser is irradiated on the entire circumference of a data code 2 with the same width as that of a black cell so as to obtain a frame-shaped auxiliary background part 3. Out of the data part 22 of the data code 2, the black cells 22A adjoining the L-shaped reading reference part 21 comprise a part of the auxiliary background part 3 surrounding the entire circumference of the reading reference part 21. The black cells comprising the auxiliary background part 3 are disposed to such an extent as to be able to recognize the width and the length of the L-shaped reading reference part 21. COPYRIGHT: (C)2004,JPO